A.A.Bondarenko
Normal waves in a rectangular elastic waveguide

Acoustic bulletin, Vol. 10 ¹ 4, (2007) p.12-27
The problem on normal wave propagation in a rectangular elastic waveguide is solved on the basis of an analytical method of superposition. Algorithms are developed for calculation of the dispersion curves and displacement fields for each type of normal waves. For a waveguide with square cross section, the dispersion relations are analyzed. The results for real, imaginary, and complex values of propagation constant are presented. The data on cutoff frequencies are systematized for five types of modes of the square waveguide. Limiting values of phase and group velocities are determined. Dependencies of displacement distribution for fundamental propagating waves versus frequency and Poisson's ratio are studied. Special features of non-propagating waves, that correspond to pure imaginary and complex roots of the dispersion equations, are investigated in detail.
KEY WORDS:
elastic waveguide, normal modes, method of superposition, the dispersion relations
TEXT LANGUAGE: Russian